Field of the Invention
This invention relates to a process of manufacturing plastic bag and film products that may be used for a multitude of purposes such as, but not limited to, fast foods, supermarkets, retail merchandise and point-of-purchase bags.
More specifically, this invention relates to a process that produces a high volume output while having the flexibility to form plastic bags and film products of an ordinary variety or of a unique, highly specific shape.
Common plastic bag styles used by retailers in fast food chains, supermarkets and general merchandise, as well as in point-of-purchase applications, are typically of the bottom seal or sideweld variety. These bags are usually gusseted along their sides or along the bottom with the open bag mouth at the top. Many of these common bags have carrying handles, usually of the strap variety or die-cut holes, and any take on unique shapes, such as the bags of U.S. Pat. No. 4,717,262 Roen, et al, U.S. Pat. No. 4,676,378 Baxley, et al., and my U.S. Pat. No. 4,759,639. Plastic bags of these varieties are typically made on bag machines, which run from 2 to 5 lanes across in order to maximize production efficiencies. Upon the final cutting and sealing operation, they are stacked up and usually die cut to create handles holes, strap handles, tabs, or unique bag shapes.
We have learned from U.S. Pat. No. 5,226,858 Snowden a method of improving the output of certain types of detachable bags by making a single intermediate die cut that leaves them interconnected at their open ends. The die cut leaves a traverse, weakened tear line that extends across the bag width, which keeps the interconnected bags together after the die cutting process. The bags are then cut and separated at the intermediate tear line, or are folded over into packs, either of which would then be packed in a shipping carton. Folding the bags over into packs will create an undesirable situation if a detachable bag pack is to be subsequently mounted onto hook type holders. The folding process will cause the bags to shingle, thereby making it very difficult to line up the mounting holes in the detachable tabs. Extra time and labor is also required in order to separate the interconnected bags, regardless of their ultimate use.
Whether a bag pack is bottom sealed or sidewelded, a process that can take a bag stack and sever it into two or more independent stacks--without being S interconnected with traverse tear lines, and incurring extra handling--would be desirable. The handling of the bag packs must be a simple easy-to-use method to ensure a quality output with minimum training. Furthermore, the process should be versatile and capable of making any number of bag styles--not just limited to detachable bags.